1. Field of the Invention
The present invention relates to a slide locking apparatus for a seat of an automobile, or the like.
2. Description of the Related Art
In the prior art, a slide locking apparatus for an automobile seat is known, as disclosed in Japanese Utility Model Application Publication No. 47-39764, for example. The slide locking apparatus disclosed in this Japanese Utility Model Application Publication No. 47-39764 comprises a lower rail which is fixed to the floor of the automobile and an upper rail which is attached in a fixed fashion to a seat. The lower rail has a plurality of second locking portions (recesses) which are aligned in a direction following the lengthwise direction of the rail (the front/rear direction of the automobile). The upper rail has one locking piece (for example, a locking hook) as a first locking part which interlocks with a second locking portion. A locked state is achieved when the locking piece is inserted into any one of the second locking portions. In this locked state, the seat is fixed in a suitable front/rear position.
In a configuration which locks by interlocking one locking piece into one second locking portion, as in the slide locking apparatus disclosed in Utility Model No. S47-39764, the force applied to the seat is applied to the abutting portion between the locking piece and the inner wall of the second locking portion (in other words, to one location). Consequently, the locking strength between the locking piece and the second locking portion may be affected.
On the other hand, it is expected that the locking strength can be improved by adopting a composition in which a plurality of locking pieces aligned in the front/rear direction are provided on a seat, for example, and this plurality of locking pieces are inserted simultaneously into a plurality of second locking portions.
However, even with a configuration of this kind, the locking strength between the locking pieces and the second locking portions may be affected. For example, as shown in FIG. 17, if the seat is moved forwards (in the X direction in FIG. 17) and the rearmost locking piece 100a of the locking pieces 100a to 100e is inserted into the forwardmost second locking portion 102a of the second locking portions 102 of the lower rail 101, then only the rearmost locking piece 100a is inserted into the forwardmost second locking portion 102. In cases such as this, force is applied to the abutting portion between the locking piece 100a and the inner wall of the second locking portion 102a (in other words, in one location). Therefore, similarly to a configuration where only one locking piece is provided as described above, the locking strength between the locking piece and the second locking portion may be affected.